Hydrogen containing silicone oil, an important organic silicon compound in the chemical industry, has always been a hot topic in chemical research for its synthesis and application. This article aims to comprehensively analyze the synthesis pathway, application fields, and unique value of hydrogen containing silicone oil in the field of chemistry.
1. Introduction to Hydrogen Containing Silicone Oil
1.1. Basic Concepts
Methyl hydrogen containing silicone oil, abbreviated as hydrogen containing silicone oil, is an important organic silicon compound with a methyl or hydrogen atom on its R group.
1.2. Synthesis Path
Product brand and synthetic raw materials
Fully hydrogen containing silicone oil, which is a compound with zero n value, is represented in the market by production brand numbers such as 202 and 802. The synthesis process mainly uses methyl D4 and 1,3,5,7-tetramethylcyclotetrasiloxane as the basic raw materials, while adding hexamethyldisiloxane or 1,1,3,3-tetramethyldisiloxane as the end capping agent. Under the guidance of a catalyst, a precise proportion of equilibrium polymerization reaction is carried out.

Selection of catalyst
Choosing the appropriate catalyst is crucial in the synthesis process of hydrogen containing silicone oil. Unlike conventional silicone oil synthesis, the synthesis of hydrogen containing silicone oil requires the use of acidic catalysts to prevent the breakage of the silicon hydrogen (Si-H) bond, which may be caused by alkaline catalysts. In industry, by-products are often prepared by hydrolyzing methyl dichlorosilane (CH3SiHCl2), which is then subjected to equilibrium polymerization with D4 and a capping agent under the action of an acidic catalyst.
Catalysts and reaction conditions
In order to maintain the activity of the catalyst and prevent its reduction by silicon hydride compounds, strong acid catalysts that are not easily reduced, such as concentrated sulfuric acid, are commonly used in industry. In addition, the hydrolysis process needs to be carried out in an appropriate solvent to avoid gel of the product. Common solvents include a mixture of ethanol, butanol, and toluene.

2. Application of hydrogen containing silicone oil
2.1. Intermediates and Reactions
Hydrogen containing silicone oil, due to its unique active Si-H bond, has become an indispensable intermediate in the synthesis of modified silicone oil. It can undergo hydrosilylation reaction with compounds containing carbon carbon double bonds, thus playing a crucial role in organic synthesis.
Synthesis of key intermediates
2.2. Crosslinking and Film Formation
Hydrogen containing silicone oil also exhibits excellent crosslinking film-forming ability. Under the catalysis of metal salt compounds, this product can undergo cross-linking reactions in a lower temperature range (140-150 ℃), thereby forming uniform and stable waterproof films on various material surfaces.
2.3. Waterproof application
With its excellent waterproof performance, hydrogen containing silicone oil is widely used in waterproof treatment of various substrates, such as fabrics, glass, ceramics, paper, leather, metals, cement, and marble. This has shown a wide range of application prospects for hydrogen containing silicone oil in multiple industrial and commercial fields.
The crosslinking reaction of hydrogen containing silicone oil is usually initiated by water and accelerated in alkaline environments. The initial step of the reaction is the hydrolysis or oxidation of silicon hydrogen bonds (Si-H), which are then converted into silanol. Subsequently, these silanols form stable siloxane bonds through condensation reactions, thus completing the crosslinking process. It is worth noting that with the addition of metal compounds such as lead, zirconium, zinc, tin, titanium, etc. as catalysts, the reaction temperature can be significantly reduced, usually to 140-150 ℃. In addition, highly active organic titanate catalysts, such as butyl titanate, can further promote crosslinking reactions. However, it should be noted that these catalysts are sensitive to moisture and are therefore typically used in anhydrous organic solvent environments.